Mosquito Activity

When will mosquito activity drop in the eastern US?

If you live in the eastern United States, you may feel like there are more mosquitoes flying around than normal. This is not your imagination.

Mosquito activity has been high throughout much of the eastern U.S. due to heavy summer rainfall.

Mosquito populations heavily rely on water for survival, as mosquito larvae and pupae are aquatic. They need a water source to develop, grow, feed and live out that life stage, according Dr. Jim Fredericks, the chief entomologist for the National Pest Management Association.

"When there is a lot of water, there is a lot of places for adult mosquitoes to lay their eggs increasing survivorship and these populations," Fredericks said. "The result is that we have these large populations of mosquitoes that are interacting with people."

The eastern U.S. experienced a particularly wet summer. Therefore, there have been reports of large mosquito populations.

In mid-September, Hurricane Florence caused historic rainfall and flooding in the Carolinas, triggering an influx in mosquitoes.

"As those floodwaters recede, we will continue to see puddles and pockets of standing water. Those are all great places for mosquitoes to lay their eggs," Fredericks said.

As those pockets start to dry up, there will still be large populations of mosquitoes that are looking for places to lay their eggs. These remaining breeding locations are often near homes in manmade watersources, such as flower pots, bird baths and children's toys that are filled with water.

"These large mosquito populations are attracted to man-made water sources, and that's why people continue to encounter them, and sometimes in larger numbers after the floodwaters dry out," Fredericks said.

Like all insects, mosquitoes are cold-blooded so they are sensitive to temperature change.

"When temperatures drop, their activity will typically drop. In the case of mosquitoes, once the temperature is consistently below 50 [degrees Fahrenheit], their activity will be reduced enough so that they aren't flying and biting," Fredericks said.

This will begin to occur first in the Northern states. For example, in Boston, Massachusetts, the normal high temperature for the day doesn't drop below 50 F until mid-November.

"While there are some highs in the 50s over the next three weeks, it's not consistently there," AccuWeather Meteorologist Courtney Spamer said.

The farther south you go, the later that time will be.

In Philadelphia, Pennsylvania, the average high temperature usually falls to 50 F at the end of November. In Washington, D.C., it occurs in early December, and in Raleigh, North Carolina, it occurs at the end of December.

"Currently in the eastern U.S, temperatures are expected to be high for the next couple of weeks, and at certain points higher than normal," Spamer said.

Therefore, mosquitoes could still be a problem in the East through the end of autumn, and possibly through the end of the year in the Carolinas.

Certain species of mosquitoes have overwintering behavior in which the adults find a protected place, such as a sewer or a storm drain, to shield them from the elements and make it through the winter.

However, it is more common that adult mosquitoes will lay their eggs, and their eggs will be able to survive the winter because they're cold-blooded.

Not all mosquitoes are able to do that, which is why some species are limited to the tropical and subtropical regions.

While mosquito levels are high, it is important that you protect yourself from mosquito bites and mosquito-borne diseases, such as Zika and West Nile Virus.

There are a number of preventative measures that can help reduce the risk of mosquitoes near your home.

"Identify those potential breeding zones that you may be inadvertently creating around your house like kitchen tools and saucers that may be underneath planted pots," Fredericks said.

If you have questions or need further assistance, you can call a pest control professional. A pest control professional can provide an extra set of eyes that you need to help identify some of these places, Fredericks added.

A pest control professional can also develop an integrative mosquito management plan, specifically for your property. The plan will help reduce the number of mosquitoes that are present around your property.